On 06/13/2014 06:08 PM, Philipp Zabel wrote:
> This disables forcing IDR frames at GOP size intervals on CODA7541 and CODA960,
> which is only needed to work around a firmware bug on CodaDx6.
> Instead, the V4L2_BUF_FLAG_KEYFRAME v4l2 buffer flag is cleared before marking
> the source buffer done for dequeueing. Userspace can set it before queueing a
> frame to force an IDR frame, to implement VFU (Video Fast Update).
I'd like to see an RFC for this feature. Rather than 'misuse' it, I think this
should be standardized. I have nothing against using KEYFRAME in order to
implement VFU (in fact, I like it!), but it should be documented and well-defined.
Regards,
Hans
>
> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> ---
> drivers/media/platform/coda.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/media/platform/coda.c b/drivers/media/platform/coda.c
> index 11e059d..cf75112 100644
> --- a/drivers/media/platform/coda.c
> +++ b/drivers/media/platform/coda.c
> @@ -1264,22 +1264,22 @@ static void coda_prepare_encode(struct coda_ctx *ctx)
> * frame as IDR. This is a problem for some decoders that can't
> * recover when a frame is lost.
> */
> - if (src_buf->v4l2_buf.sequence % ctx->params.gop_size) {
> - src_buf->v4l2_buf.flags |= V4L2_BUF_FLAG_PFRAME;
> - src_buf->v4l2_buf.flags &= ~V4L2_BUF_FLAG_KEYFRAME;
> - } else {
> + if ((src_buf->v4l2_buf.sequence % ctx->params.gop_size) == 0)
> src_buf->v4l2_buf.flags |= V4L2_BUF_FLAG_KEYFRAME;
> + if (src_buf->v4l2_buf.flags & V4L2_BUF_FLAG_KEYFRAME)
> src_buf->v4l2_buf.flags &= ~V4L2_BUF_FLAG_PFRAME;
> - }
> + else
> + src_buf->v4l2_buf.flags |= V4L2_BUF_FLAG_PFRAME;
>
> if (dev->devtype->product == CODA_960)
> coda_set_gdi_regs(ctx);
>
> /*
> - * Copy headers at the beginning of the first frame for H.264 only.
> - * In MPEG4 they are already copied by the coda.
> + * Copy headers in front of the first frame and forced I frames for
> + * H.264 only. In MPEG4 they are already copied by the CODA.
> */
> - if (src_buf->v4l2_buf.sequence == 0) {
> + if (src_buf->v4l2_buf.sequence == 0 ||
> + src_buf->v4l2_buf.flags & V4L2_BUF_FLAG_KEYFRAME) {
> pic_stream_buffer_addr =
> vb2_dma_contig_plane_dma_addr(dst_buf, 0) +
> ctx->vpu_header_size[0] +
> @@ -3245,6 +3245,8 @@ static void coda_finish_encode(struct coda_ctx *ctx)
> src_buf->v4l2_buf.flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
> dst_buf->v4l2_buf.timecode = src_buf->v4l2_buf.timecode;
>
> + /* Clear keyframe flag so userspace can misuse it to force an IDR frame */
> + src_buf->v4l2_buf.flags &= ~V4L2_BUF_FLAG_KEYFRAME;
> v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_DONE);
>
> dst_buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
>
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